(1) Field of the Invention
The present invention relates generally to acoustic signal detection in the presence of flow noise, and more particularly to a system and method for detecting an acoustic signal in the presence of flow noise produced by the turbulent flow field that develops about a hosewall of a towed array being towed through the water.
(2) Description of the Prior Art
Currently, towed arrays have a limited tow speed range over which they can operate effectively because of flow noise. Flow noise, which can mask an acoustic signal of interest, is generally divided into direct noise from the predominantly non-acoustic turbulent boundary layer wall pressure fluctuations and flow induced noise due to structural vibrations excited by the turbulent boundary layer. Existing towed array systems designed to mitigate against or reduce direct flow noise effects are currently only effective over a specific towing speed and frequency range. However, turbulent wall pressure fluctuations resulting from the turbulent boundary layer exist over the entire array at all operating speeds.